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authorHeiko Carstens <hca@linux.ibm.com>2023-01-09 11:51:20 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-01-18 09:26:42 +0100
commitfbf628a77f539b1907686f2c185f1df67eea3fdd (patch)
tree163085d040b1cc5aba428f27eb098e2af2fbafca /arch
parentf3c19d08956e6d3337e29ee967fe54cf6fd860ed (diff)
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s390/percpu: add READ_ONCE() to arch_this_cpu_to_op_simple()
commit e3f360db08d55a14112bd27454e616a24296a8b0 upstream. Make sure that *ptr__ within arch_this_cpu_to_op_simple() is only dereferenced once by using READ_ONCE(). Otherwise the compiler could generate incorrect code. Cc: <stable@vger.kernel.org> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/percpu.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h
index 50f6661ba566..026a94b03a3c 100644
--- a/arch/s390/include/asm/percpu.h
+++ b/arch/s390/include/asm/percpu.h
@@ -31,7 +31,7 @@
pcp_op_T__ *ptr__; \
preempt_disable_notrace(); \
ptr__ = raw_cpu_ptr(&(pcp)); \
- prev__ = *ptr__; \
+ prev__ = READ_ONCE(*ptr__); \
do { \
old__ = prev__; \
new__ = old__ op (val); \